Note: Descriptions are shown in the official language in which they were submitted.
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Plastic Bag Making Apparatus
Technical Field
The invention relates to an apparatus for successively making plastic
bags.
Background
There has heretofore been proposed a plastic bag including panel
portions, side gusset portions and a bottom gusset portion, as disclosed in
Japanese Patent Publication No. 3,655,627. Each of the panel portions has
opposite side edges along which the side gusset portions extend. Each of the
panel portions further has opposite and edges along one of which the bottom
gusset portion extends. Each of the side gusset portions has opposite end
portions at one of which an auxiliary gusset portion is formed. The bottom
gusset portion is combined with the auxiliary gusset portion. The plastic bag
can therefore be enlarged by the side gusset portions to obtain an increased
capacity. A flat bottom surface can be formed by the bottom gusset portion
to make the plastic bag stand stably. The plastic bag is called a rectangular
bottom bag.
In addition to the side gusset portions and the bottom gusset portion,
the plastic bag may further include an additional bottom gusset portion, as
disclosed in Japanese Patent Publication No. 4,108,846. The bottom gusset
portion extends along one of the end edges of panel portion while the
additional bottom gusset portion extends along the other end edge. In
addition to the auxiliary gusset portion formed at one of the end portions of
side gusset portion, an auxiliary gusset portion is formed at the other end
portion. The additional bottom gusset portion is combined with the auxiliary
gusset portion. In this case, the plastic bag can be shaped into a rectangular
parallelepiped to have an appearance of box when being filled with content.
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A flat top surface is formed by the bottom gusset portion while a flat bottom
surface is formed by the additional bottom gusset portion. The plastic bag is
therefore high in efficiency of being filled. The plastic bags can be pilled
up
conveniently.
The plastic bag of each of the publications is therefore expected to be
used widely in the future. In this connection, it is desired to make the
plastic bag have an added value. In particular, it is desired to make the
plastic bag include an opening in position for discharge of content.
It is therefore an object of the invention to provide a new and
improved apparatus for successively making plastic bags each of which is
called a rectangular bottom bag.
Another object is to make the plastic bag include an opening in
position.
Summary of the Invention
According to the invention, the apparatus is arranged to successively
make plastic bags each of which includes panel portions, side gusset portions
and a bottom gusset portion. Each of the side gusset portions has opposite
end portions at one of which an auxiliary gusset portion is formed. The
bottom gusset portion is combined with the auxiliary gusset portion. The
plastic bag further includes an opening formed between bottom protrusions
protruding from the bottom gusset portion,
The apparatus includes panel material feeding means by which upper
and lower webs of panel material are opposed to and superposed on each
other and fed longitudinally thereof and intermittently. Each of the webs of
panel material has opposite side edges. The panel portions are formed by the
webs of panel material, The apparatus further includes side gusset material
supply means by which a sheet of side gusset material is folded into halves,
superposed into two layers and then supplied to and interposed between the
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webs of panel material to extend widthwise thereof whenever the webs of
panel material are fed intermittently. The sheet of side gusset material has
opposite end portions one of which is spaced from one of the side edges of
panel material. The side gusset portion and the auxiliary gusset portion are
formed by the sheet of side gusset material. The apparatus further includes
temporarily fixing means by which one of the webs of panel material is
temporarily fixed to one of the layers of side gusset material, the other web
of
panel material being temporarily fixed to the other layer of side gusset
material, at one of the end portions of side gusset material after the sheet
of
side gusset material is interposed. The apparatus further includes joint
means by which the webs of panel material are joined to each other along a
longitudinal joint line predetermined adjacent to one of the side edges of
panel
material. The apparatus further includes guide moans by which each of the
webs of panel material is guided to be deformed from one of the side edges
thereof after being temporarily fixed and joined and when being fed so that
one of the webs of panel material can be folded along a longitudinal first
folded line spaced from the longitudinal joint line to make the webs of panel
material open and make an open surface formed on the webs of panel material.
One of the layers of side gusset material is folded along the longitudinal
first
folded line to make the layers of side gusset material open along with the
auxiliary gusset portion and make an open surface formed on the layers of
auxiliary gusset portion. One of the webs of panel material is turned along a
longitudinal turned line formed between the longitudinal joint line and the
longitudinal first folded line to make a turned portion formed in one of the
webs of panel material and superposed on the open surfaces of the webs of
panel material and the layers of auxiliary gusset portion. The other web of
panel material is folded along a longitudinal second folded line spaced from
the longitudinal joint line to make a folded portion formed in the other web
of
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panel material and superposed on the open surfaces of the webs of panel
material and the layers of auxiliary gusset portion. The bottom gusset
portion is formed by the turned portion and the folded portion. The opening
is formed between the bottom protrusions which are formed between ones of
the side edges of panel material and the longitudinal joint line.
In a preferred embodiment, one of the webs of panel material is folded
along the longitudinal first folded line and folded back along a longitudinal
folded back line to make a folded back portion formed in one of the webs of
panel material. The turned portion comprises the folded back portion. The
longitudinal turned line comprises the longitudinal folded back line.
One of the webs of panel material may be slit along a longitudinal slit
line after being temporarily fixed and joined. One of the webs of panel
material is then folded along the longitudinal first folded line. The turned
portion is formed between the longitudinal joint line and the longitudinal
slit
line. The longitudinal turned line comprises the longitudinal slit line.
The apparatus further includes cross seal means by which the webs of
panel material and the sheet of side gusset material are heat sealed with each
other widthwise of the webs of panel material after the webs of panel material
are folded and turned and whenever the webs of panel material are fed
intermittently.
The apparatus further includes additional bottom gusset material
supply means by which a web of additional bottom gusset material is supplied
to and interposed between the webs of panel material to extend longitudinally
thereof.
The apparatus further includes longitudinal seal means by which the
webs of panel material and the web of additional bottom gusset material are
heat sealed with each other longitudinally of the webs of panel material
whenever the webs of panel material are fed intermittently. The plastic bag
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further includes an additional bottom gusset portion formed by the web of
additional bottom gusset material.
The apparatus further includes a cutter by which the webs of panel
material are cut widthwise thereof after the webs of panel material are heat
sealed and whenever the webs of panel material are fed intermittently.
The apparatus further includes zipper supply means by which a zipper
is supplied to and interposed between the webs of panel material to extend
along the longitudinal joint line. The joint means comprises zipper seal means
by which the webs of panel material and the zipper are heat sealed with each
other so that the webs of panel material can be joined to each other. The
opening is formed by the zipper.
The joint means may comprise spot seal means by which the webs of
panel material are spot sealed with each other to be joined to each other at a
position corresponding to the sheet of side gusset material whenever the
webs of panel material are fed intermittently. The opening is formed between
points at which the webs of panel material are spot sealed.
The longitudinal first folded line is spaced from the longitudinal joint
line at a first distance. The longitudinal turned line is spaced from the
longitudinal joint line at a second distance. The longitudinal second folded
line is also spaced from the longitudinal joint line at the second distance.
The second distance is half of the first distance. The sheet of side gusset
material extends widthwise of the webs of panel material so that one of the
and portions of side gusset material can be spaced from the longitudinal join
line at the second distance.
Brief Description of the Drawings
Fig. 1 is a plan view of a preferred embodiment of the invention.
Fig. 2 is a side view of the apparatus of Fig. 1.
Fig. 3 is an explanatory view of a plastic bag obtained by the
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apparatus of Fig. 1.
Fig. 4 is an explosive view of the plastic bag of Fig. 3.
Fig. 5 is a perspective view of the plastic bag of Fig. 3 when being
filled with content.
Fig. 6 is a perspective view of another embodiment.
Fig. 7 is a side view of the apparatus of Fig. 6.
Fig. 8 is a plan view of another embodiment.
Fig. 9 is a plan view of another embodiment.
Fig. 10 is an explosive view of a plastic bag obtained by the apparatus
of Fig. 8.
Fig. 11 is a plan view of another embodiment.
Fig. 12 is a plan view of another embodiment.
Fig. 13 is a perspective view of a plastic bag obtained by the
apparatus of Fig. 11.
Best Mode to Carry Out the Invention
Embodiments of the invention are as follows.
Turning now to the drawings, Fig. 1 illustrates an apparatus for
successively making plastic bags, according to the invention. Each of the
plastic bags includes panel portions 1 and 2, side gusset portions 3 and a
bottom gusset portion 4 and 5, as shown in Fig. 3 and as in the case of the
plastic bag of Japanese Patent Publication No. 3,655,627. The panel portions
1 and 2 are superposed on each other, as shown in Fig. 4. Each of the panel
portions 1 and 2 includes opposite side edges 6 along which the side gusset
portions 3 extend. Each of the side gusset portions 3 is folded into halves,
superposed into two layers and interposed between the panel portions 1 and 2.
The panel portions 1 and 2 and the side gusset portions 3 are heat sealed
with each other along the side edges 6 of panel portions 1 and 2 so that heat
sealed lines 7 can be formed along the side edges 6 of panel portions 1 and 2.
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Each of the panel portions 1 and 2 further includes opposite end edges along
one of which 8 and 9 the bottom gusset portion 4 and 5 extends. Each of the
side gusset portions 3 has opposite end portions one of which is folded at an
angle of 45 so that an auxiliary gusset portion 10 can be formed at one of
the end portions. The bottom gusset portion 4 and 5 is combined with the
auxiliary gusset portion 10.
In addition, one of the panel portions 1 is folded along a widthwise
first folded line 11 to make the panel portions 1 and 2 open and make an open
surface formed on the panel portions 1 and 2. One of the layers of side
gusset portion 3 is folded along a widthwise side gusset folded line 12 to
make
the layers of side gusset portion 3 open, make the layers of auxiliary gusset
portion 10 open and make an open surface formed on the layers of auxiliary
gusset portion 10. Furthermore, one of the panel portions 1 and 2 is turned
along a widthwise turned line 8 to make a turned portion 4 formed in one of
the panel portions 1 and superposed on the open surfaces of panel portion 1
and auxiliary gusset portion 10. For example, one of the panel portions 1 is
folded back along a widthwise folded back line 8 to make a folded back portion
4 formed in one of the panel portions 1 and superposed on the open surfaces
of panel portion 1 and auxiliary gusset portion 10. In this case, the turned
portion 4 comprises the folded back portion. The widthwise turned line 8
comprises the widthwise folded back line. The other panel portion 2 is folded
along a widthwise second folded line 9 to make a folded portion 5 formed in
the other panel portion 2 and superposed on the open surfaces of panel
portion 2 and auxiliary gusset portion 10. The bottom gusset portion 4 and 5
is therefore formed by the turned portion 4 and the folded portion 5 and
combined with the auxiliary gusset portion 10. One of the opposite end
edges 8 and 9 of panel portions 1 and 2 is formed by the widthwise turned line
8 and the widthwise folded line 9 of panel portions 1 and 2. The bottom
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gusset portion 4 and 5 and the auxiliary gusset portions 10 are heat sealed
with each other along the side edges 6 of panel portions 1 and 2 so that heat
sealed lines 7 can be formed along the side edges 6 of panel portions 1 and 2.
The bottom gusset portion 4 and 5 comprises the turned portion 4 and
the folded portion 5 including free end edges 13 and 14. The turned portion 4
and the folded portion 5 are folded along widthwise third and forth folded
lines
15 and 16 predetermined adjacent to the free and edges 13 and 14 of turned
portion 4 and folded portion 5 so that considerable portions 17 and 18 can be
formed between the free end edges 13 and 14 and the widthwise third and
fourth folded lines 15 and 16 and superposed into two layers. The plastic bag
includes an opening formed between bottom protrusions 17 and 18 protruding
from the bottom gusset portion 4 and 5, the bottom protrusions 17 and 18
being formed by the considerable portions 17 and 18.
The respective lines 8, 9, 1 1 , 12, 15 and 16 are parallel to each other.
In the plastic bag, the bottom gusset portion 4 and 5 includes opposite
side edges contiguous to the end edges 8 and 9 of panel portions 1 and 2.
The bottom protrusions 17 and 18 are formed between the side edges of
bottom gusset portion 4 and 5. The widthwise first folded line 11 is spaced
from the widthwise third and fourth folded lines 15 and 16 at a first
distance.
The widthwise turned line 8 is spaced from the third and fourth folded lines
15
and 16 at a second distance. The widthwise second folded line 9 is also
spaced from the widthwise third and fourth folded lines 15 and 16 at the
second distance. The second distance is half of the first distance. The
bottom protrusions 17 and 18 are therefore formed at the center of the
bottom gusset portion 4 and 5 widthwise thereof.
In addition, the plastic bag includes a zipper 19. The zipper 19 has
been used generally in itself. The zipper 19 includes a male member formed
integrally with a tape and fitted into a female member which is also formed
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integrally with a tape. The zipper 19 is interposed between the bottom
protrusions 17 and 18 which are formed by the considerable portions 17 and
18, as described above. The bottom protrusions 17 and 18 are heat sealed
with the tapes of male and female members respectively so that heat sealed
lines 20 and 21 can be formed along the zipper 19. One of the heat sealed
lines 20 is formed on one of the opposite sides of male and female members.
The other heat sealed line 21 is formed on the other side of male and female
members and adjacent to the widthwise folded lines 15 and 16. It should
therefore be understood that the plastic bag includes the opening formed by
the zipper 19.
The plastic bag further includes an additional bottom gusset portion
22, as in the case of the plastic bag of Japanese Patent Publication No.
4,108,846. The bottom gusset portion 4 and 5 extends along one of the end
edges 8 and 9 of panel portions 1 and 2 while the additional bottom gusset
portion 22 extends along the other and edges 23. The additional bottom
gusset portion 22 is folded into halves, superposed into two layers and
interposed between the panel portions 1 and 2. In addition, each of the side
gusset portions 3 has the other end portion folded at an angle of 45 so that
an auxiliary gusset portion 24 can be formed at the other end portion, as in
the case of one of the end portions of side gusset portion 3. The auxiliary
gusset portion 24 is folded into halves, superposed into two layers and
interposed between the layers of side gusset portion 3. The additional
bottom gusset portion 22 is interposed between the layers of auxiliary gusset
portion 24. The auxiliary gusset portion 24 and the additional bottom gusset
portion 22 are heat sealed with each other along the side edges 6 of panel
portions 1 and 2 so that heat sealed lines 7 can be formed along the side
edges 6 of panel portions 1 and 2. The panel portions 1 and 2 and the
additional bottom gusset portion 22 are heat sealed with each other along the
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other end edges 23 of panel portions 1 and 2 so that heat sealed lines 7 can
be formed along the other end edges 23 of panel portions 1 and 2.
The plastic bag can therefore be enlarged by the side gusset portions
3 to obtain an increased capacity, as shown in Fig, 5. A flat bottom surface
is formed by the additional bottom gusset portion 22 to make the plastic bag
stand stably, when being filled with content. A flat top surface is formed by
the bottom gusset portion 4 and 5 so that the plastic bag can be shaped into
a rectangular parallelepiped to have an appearance of box. The plastic bag is
therefore high in efficiency of being filled. The bottom protrusions 17 and 18
can be folded along the widthwise third and fourth folded lines 15 and 16 and
superposed on the bottom gusset portion 4 or 5 after being filled so that the
plastic bags can be pilled up conveniently.
In addition, the plastic bag includes the opening formed between the
protrusions 17 and 18 of bottom gusset portion 4 and 5 for discharge of
content. The zipper 19 can make the opening open and close.
In order to successively make the plastic bags of Fig. 3, the apparatus
includes panel material feeding means by which upper and lower webs of panel
material 1 and 2 are opposed to and superposed on each other and fed
longitudinally thereof and intermittently. Each of the webs of panel material
1 and 2 has opposite side edges 13, 14 and 22. The webs of panel material 1
and 2 comprise plastic films by which the panel portions 1 and 2 of Fig. 3 are
formed. In the embodiment, the panel material feeding means comprises feed
rollers 25 and 26, as shown in Fig. 2, the upper web of panel material I being
supplied downwardly and directed to the feed rollers 25. The lower web of
panel material 2 is supplied horizontally and directed to the feed rollers 25
so
that the webs of panel material 1 and 2 can be opposed to and superposed on
each other. The webs of panel material 1 and 2 are then directed to the feed
rollers 26. The feed rollers 25 and 26 are rotated by a drive motor so that
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the webs of panel material 1 and 2 can be fed longitudinally thereof and
intermittently.
The apparatus further includes side gusset material supply means 27
by which a sheet of side gusset material 3 is folded into halves, superposed
into two layers and then supplied to and interposed between the webs of panel
material 1 and 2 to extend widthwise thereof whenever the webs of panel
material 1 and 2 are fed intermittently. The sheet of side gusset material 3
has opposite end portions one of which is spaced from one of the opposite
side edges 13 and 14 of panel material 1 and 2. The .sheet of side gusset
material 3 comprises a plastic film by which the side gusset portion 3 and the
auxiliary portions 10 and 24 of Fig. 3 are formed. In the embodiment, the
sheet of side gusset material 3 has a double width, which is previously folded
into halves on the opposite sides of the longitudinal centerline thereof to be
superposed into two layers, as in the case of the apparatus of Japanese
Patent Publication No. 3,655,627. The sheet of side gusset material 3 is
supplied to and put on the lower web of panel material 2 to extend widthwise
thereof before the webs of panel material I and 2 are superposed on each
other and whenever the webs of panel material 1 and 2 are fed intermittently.
The webs of panel material 1 and 2 are then superposed on each other so that
the sheet of side gusset material 3 can be interposed between the webs of
panel material 1 and 2. It should be noted that the side gusset material
supply means 27 has the same structure as that of Japanese Patent
Publication No. 3,655,627. No reference is therefore made to the structure
herein.
In the embodiment, the sheet of side gusset material 3 is supplied by
the side gusset material supply means 27 without making an auxiliary gusset
portion 10 formed at one of the end portions of side gusset material 3.
However, an auxiliary gusset portion 24 is formed at the other end portion of
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side gusset material 3 by making the other end portion folded at an angle of
45 .
The apparatus further includes additional bottom gusset material
supply means 28 by which a web of additional bottom gusset material 22 is fed
longitudinally thereof, folded into halves and supplied to and interposed
between the webs of panel material 1 and 2 to extend longitudinally thereof.
The web of additional bottom gusset material 22 comprises a plastic film by
which the additional bottom portion 22 of Fig. 3 is formed. In the embodiment,
the web of additional bottom gusset material 22 is supplied to and put on the
lower web of panel material 2 and interposed between the layers of auxiliary
gusset portion 24 to extend longitudinally of the lower web of panel material
2.
The webs of panel material 1 and 2 are then superposed on each other so that
the web of additional bottom gusset material 22 can be interposed between
the webs of panel material 1 and 2.
The apparatus further includes temporarily fixing means by which one
of the webs of panel material I is temporarily fixed to one of the layers of
side gusset material 3, the other web of panel material 2 being temporarily
fixed to the other layer of side gusset material 3 at one of the end portions
of
side gusset material 3 after the sheet of side gusset material 3 and the web
of
additional bottom gusset material 22 are interposed. For example, the
temporarily fixing means comprises spot seal means 29 by which the upper
web of panel material 1 is spot sealed with the upper layer of side gusset
material 3 to be temporarily fixed thereto, the lower web of panel material 2
being spot sealed with the lower layer of side gusset material 3 to be
temporarily fixed thereto at one of the end portions of side gusset material
3.
The apparatus further includes joint means by which the webs of panel
material 1 and 2 are joined to each other along a longitudinal joint line
predetermined adjacent to one of the opposite side edges 13 and 14 of panel
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material 1 and 2. In the embodiment, the apparatus further includes zipper
supply means 30 by which a zipper 19 is fed longitudinally thereof and
supplied to and interposed between the webs of panel material 1 and 2 to
extend along the longitudinal joint line. For example, the zipper 19 is
supplied to the lower web of panel material 2 to extend longitudinally thereof
before the webs of panel material 1 and 2 are superposed. The webs of panel
material 1 and 2 are then superposed on each other so that the zipper 19 can
be interposed between the webs of panel material 1 and 2. The joint means
comprises zipper seal means 31 by which the webs of panel material 1 and 2
and the zipper 19 are heat sealed with each other so that heat sealed lines 20
and 21 can be formed along the zipper 1 9. One of the heat sealed line 20 is
formed on one of the opposite sides of the zipper 19 while the other heat
sealed line 21 is formed on the other side of the zipper 19. The webs of
panel material 1 and 2 are joined to each other by the zipper 19 at a position
adjacent to the other sealed line 21. It should therefore be understood that
the webs of panel material 1 and 2 are joined to each other along the
longitudinal joint line formed by the zipper 19. Each of the webs of panel
material 1 and 2 includes one of the side edges 13 and 14 by which the free
end edges 13 and 14 of Fig. 3 are formed and the sealed lines 20 and 21 by
which the sealed lines 20 and 21 of Fig. 3 are formed.
The apparatus further includes guide means by which each of the webs
of panel material 1 and 2 is guided to be deformed from one of the side edges
13 and 14 after being temporarily fixed and joined and when being fed so that
one of the webs of panel material 1 can be folded along a longitudinal first
folded line 11 spaced from the longitudinal joint line. In addition, one of
the
webs of panel material 1 is turned along a longitudinal turned line 8 formed
between the longitudinal joint line and the longitudinal first folded line 11
to
make a turned portion 4 formed in one of the webs of panel material 1. In
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the embodiment, one of the webs of panel material 1 is folded along the
longitudinal first folded line 11 and folded back along a longitudinal folded
back line 8 to make a folded back portion 4 formed in one of the webs of panel
material 1. The turned portion 4 comprises the folded back portion 4. The
longitudinal turned line 8 comprises the longitudinal folded back line 8. At
the same time, the other web of panel material 2 is folded along a
longitudinal
second folded line 9 spaced from the longitudinal joint line. The webs of
panel material 1 and 2 are folded and turned under the condition of being
joined to each other along the longitudinal joint line.
In the embodiment, the guide means comprises guide rollers 32 and 33,
the webs of panel material 1 and 2 passing through the guide roller 32 to be
directed to and pulled and lowered by the guide roller 33. In addition, the
webs of panel material 1 and 2 are guided by the guide rollers 32 and 33 when
being fed and under tension so that the upper web of panel material 1 can be
folded along the longitudinal first folded line 11 to make the webs of panel
material 1 and 2 open and make an open surface formed on the webs of panel
material 1 and 2. In addition, the upper web of panel material 1 has been
temporarily fixed to the upper layer of side gusset material 3, the lower web
of panel material 2 being temporarily fixed to the lower layer of side gusset
material 3 at one of the end portions of the side gusset material 3, as
described previously. The upper layer of side gusset material 3 is therefore
pulled by the upper web of panel material 1 folded along the longitudinal
first
folded line 11 while the lower layer of side gusset material 3 is held by the
lower web of panel material 2 so that the sheet of side gusset material 3 is
folded at an angle of 45 to make an auxiliary gusset portion 10 formed at the
end portion, make the layers of side gusset material 3 open along with the
auxiliary gusset portion 10 and make an open surface formed on the layers of
auxiliary gusset portion 10, at one of the end portions of side gusset
material
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3. In addition, the upper web of panel material 1 is folded back and turned
along the longitudinal turned line 8 to make the folded back or turned portion
4 formed in the upper web of panel material 1 and superposed on the open
surfaces of the webs of panel material 1 and 2 and the layers of auxiliary
gusset portion 10. At the same time, the lower web of panel material 2 is
folded along the longitudinal second folded line 9 to make a folded portion 5
formed in the other web of panel material 2 and superposed on the open
surfaces of the webs of panel material 1 and 2 and the layers of auxiliary
gusset portion 10.
In addition, the longitudinal first folded line 11 is spaced from the
longitudinal joint line at a first distance. The longitudinal turned line 8 is
spaced from the longitudinal joint line at a second distance. The longitudinal
second folded line 9 is also spaced from the longitudinal joint line at the
second distance. The second distance is half of the first distance. The
sheet of side gusset material 3 extends widthwise of the webs of panel
material 1 and 2 so that one of the opposite end portions of side gusset
material 3 can be spaced from the longitudinal joint line at the second
distance. It should therefore be understood that the upper web of panel
material 1 is folded along the longitudinal first folded line 11 to make the
open
surfaces on the webs of panel material 1 and 2 and the layers of auxiliary
gusset portion 10, as described previously. In addition, the upper web of
panel material 1 is folded back or turned along the longitudinal turned line 8
to
make the turned portion 4 superposed on the open surface of panel material 1
and auxiliary gusset portion 10. The lower web of panel material 2 is folded
along the second folded line 9 to make the folded portion 5 superposed on the
open surfaces of panel material 2 and auxiliary gusset portion 10.
The turned portion 4 and the folded portion 5 are then kept being
joined to each other along the longitudinal joint line and superposed on the
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open surfaces of panel material 1 and 2 and auxiliary gusset portion 10, The
webs of panel material 1 and 2 includes the longitudinal first folded line 11,
the longitudinal turned line 8 and the longitudinal second folded line 9 by
which the widthwise first folded line 11, the widthwise turned line 8 and the
widthwise second folded line 9 of Fig. 3 are formed.
In addition, the webs of panel material 1 and 2 include considerable
portions 17 and 18 formed between the side edges 13 and 14 and the
longitudinal joint line. The considerable portions 17 and 18 are folded along
the longitudinal joint line to be superposed on the turned portion 4 under
tension between the guide rollers 32 and 33 to make one of the widthwise
third and fourth folded lines 15 and 16 of Fig. 3 formed. The considerable
portions 17 and 18 may be folded reversely after making the plastic bag to
make the other folded line formed. The plastic bag includes the bottom
gusset portion 4 and 5 formed by the turned portion 4 and the folded portion 5
and the bottom protrusions 17 and 18 formed by the considerable portions 17
and 18.
The apparatus further includes cross seal means 34 by which the webs
of panel material 1 and 2 and the sheet of side gusset material 3 are heat
sealed with each other widthwise of the webs of panel material 1 and 2 after
the webs of panel material 1 and 2 are folded and turned and whenever the
webs of panel material 1 and 2 are fed intermittently. The turned portion 4
and the folded portion 5 are heat sealed with the auxiliary gusset portion 10,
the web of additional bottom gusset material 22 being heat sealed with the
auxiliary gusset portion 24, by the cross seal means 34. The apparatus
further includes longitudinal seal means 35 by which the webs of panel
material 1 and 2 and the web of additional bottom gusset material 22 are heat
sealed with each other longitudinally of the webs of panel material 1 and 2
whenever the webs of panel material 1 and 2 are fed intermittently. The
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apparatus therefore makes the heat sealed line 7 of Fig. 3 formed.
The apparatus further includes a cutter 36 by which the webs of panel
material 1 and 2 are cut widthwise thereof after the webs of panel material 1
and 2 are heat sealed and whenever the webs of panel material 1 and 2 are
fed intermittently. They are cut at the position of side gusset portion 3. In
the embodiment, the webs of panel material 1 and 2 and the sheet of side
gusset material 3 are cut'along the longitudinal centerline of side gusset
material 3. The apparatus can therefore successively make the plastic bags
of Fig. 3.
The plastic bag therefore includes the bottom gusset portion 4 and 5
formed by the turned portion 4 and the folded portion 5, the bottom
protrusions 17 and 18 formed by the considerable portions 17 and 18 and the
opening formed between the bottom protrusions 17 and 18. The plastic bag
further includes the zipper 19 by which the opening is formed.
Fig. 6 illustrates another embodiment in which the guide means
comprises guide rollers 37 and 38. The webs of panel material I and 2 pass
through the guide roller 37 to be directed to and pulled and lowered by the
guide roller 38, as in the case of the embodiment of Fig. 1. The guide roller
38 is cantilevered to have a free end disposed at the position of longitudinal
first folded line 11. The webs of panel material 1 and 2 are changed in
direction at an acute angle about the guide roller 37 and about the guide
roller
38, as shown in Fig. 7. The webs of panel material 1 and 2 are then directed
to and sandwiched between pinch rollers 39. The webs of panel material 1
and 2 are therefore guided by the guide rollers 37 and 38 and the pinch
rollers
39 so that the upper web of panel material 1 can be deformed at the free end
of guide roller 38 to be folded along the longitudinal first folded line 11
and
folded back and turned along the longitudinal turned line 8. The lower web of
panel material 2 is folded along the longitudinal second folded line 9. The
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considerable portions 17 and 18 are formed between the side edges 13 and 14
and the longitudinal joint line, folded along the longitudinal joint line and
superposed on the turned portion 4.
In each of the embodiments of Figs. 1 and 6, the apparatus may
further include creasing means disposed upstream of the guide means so that
the webs of panel material 1 and 2 can be directed to the creasing means to
make creases formed along the longitudinal turned line 8 and the longitudinal
second folded line 9. The apparatus may further include perforating means
disposed upstream of the guide means so that the webs of panel material 1
and 2 can be directed to the perforating means to make perforations formed
along the longitudinal turned line 8 and the longitudinal second folded line
9.
In these case, the webs of panel material 1 and 2 are then folded, folded back
and turned without difficulty when being guided by the guide means. It is
preferable to make the turned portion 4 heat sealed along the longitudinal
turned line 8 and make the folded portion 5 heat sealed along the longitudinal
second folded line 9 after the perforations are formed along the longitudinal
turned line 8 and the longitudinal second folded line 9 and the webs of panel
material 1 and 2 are folded and turned, to be free of leakage from the
perforations.
Fig. 8 illustrates another embodiment in which one of the webs of
panel material 1 is directed to a slitting blade 40 to be slit along a
longitudinal
slit line 8 after being temporarily fixed and joined, for example in the
embodiment of Fig. 1. The webs of panel material 1 and 2 are then guided by
the guide means so that one of the webs of panel material 1 can be folded
along the longitudinal folded line 11 to make the webs of panel material 1 and
2 open, the open surface formed on the webs of panel material 1 and 2, make
the layers of side gusset material 3 open, make the auxiliary gusset portion
10
formed and make the open surface formed on the layers of auxiliary gusset
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portion 10. In this case, one of the webs of panel material 1 is slit and
separated previously so that one of the webs of panel material 1 can be
deformed from the longitudinal slit line 8 and folded along the longitudinal
first
folded line 11. One of the webs of panel material 1 is therefore turned
eventually to make a turned portion 4 formed between the longitudinal joint
line and the longitudinal slit line 8 and superposed on the open surfaces of
panel material 1 and auxiliary gusset portion 10. The longitudinal turned line
8 comprises the longitudinal slit line 8. The other web of panel material 2 is
folded along the longitudinal second folded line 9 to make the folded portion
5
superposed on the open surfaces of panel material 2 and auxiliary gusset
portion 10.
In addition, the webs of panel material 1 and 2 and the sheet of side
gusset material 3 are heat sealed with each other by the cross seal means 34
after the webs of panel material 1 and 2 are folded and turned, as in the case
of the embodiment of Fig. 1. The webs of panel material 1 and 2 and the web
of additional auxiliary gusset material 22 are then heat sealed with each
other
by the longitudinal seal means 35. Furthermore, in the embodiment of Fig. S.
one of the webs of panel material 1 is directed to longitudinal seal means 41
so that the turned portion 4 can be heat sealed and closed along the
longitudinal turned line 8 to restore one of the webs of panel material 1
slit.
A plate 42 may be interposed between the folded portions of panel material 1
folded along the longitudinal first folded line 11 to make the turned portion
4
heat sealed as it is. The other web of panel material 2 may be directed to
longitudinal heat seal means 43 to make the folded portion 5 heat sealed along
the longitudinal second folded line 9. In this case, heat sealed lines are
formed along the end edges 8 and 9 of panel portions 1 and 2, as shown in Fig.
10.
In the embodiment of Fig. 8. a spatula 45 may be inserted through the
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longitudinal slit line 8 so that the web of panel material 2. and the sheet of
side gusset material 3 can be guided by the spatula 45 to be folded along the
longitudinal second folded line 9 adequately after the web of panel material 1
is slit and when the webs of panel material 1 and 2 and the sheet of side
gusset material 3 are folded by the guide rollers 32 and 33.
In each of the embodiments, it is not indispensable that the joint
means comprises the zipper seal means 31. Fig. 11 illustrates another
embodiment in which a longitudinal joint line 46 is predetermined adjacent to
the side edges 13 and 14 of panel material 1 and 2. The joint means
comprises spot seal means 47 disposed along the longitudinal joint line 46, by
which the webs of panel material 1 and 2 are spot sealed with each other to
be joined to each other at a position corresponding to the sheet of side
gusset material 3 whenever the webs of panel material 1 and 2 are fed
intermittently. The webs of panel material I and 2 are then guided by the
guide means to be folded and turned so that the plastic bag can include the
bottom protrusions 17 and 18 formed between the end edges 13 and 14 and
the longitudinal joint line 46 and the opening formed between points at which
the webs 1 and 2 are spot sealed, as shown in Fig. 13.
Fig. 12 illustrates another embodiment in which in addition to the spot
seal means 47, the joint means includes longitudinal seal means 48 by which
the webs of panel material 1 and 2 are heat sealed along the side edges 13
and 14 to be joined to each other. The webs of panel material 13 and 14 are
then slit along the side edges 13 and 14 after being folded and turned, to
make the heat sealed portion removed and the opening formed.
